1. Field of the Invention
The present invention relates to measurement of a density of a catalyst or promoter component in a carrier to which the catalyst or promoter is attached using an electromagnetic wave (frequency thereof is equal to or more than 0.01 [THz], and equal to or less than 100 [THz]) (such as a terahertz wave (frequency thereof is equal to or more than 0.03 [THz], and equal to or less than 10 [THz]), for example).
2. Description of the Prior Art
Conventionally, a carrier made of a ceramic has been immersed in a solution or suspension of a catalyst or promoter, the catalyst or promoter attaches to the carrier, and an oxidation catalyst for automobiles and the like and an electrode for a fuel cell are then obtained.
It should be noted that the applicant does not know prior art documents describing the measurement of the quantity of the catalyst or promoter (such as density) attached to the carrier.